Artificial hand



ZAKBGS F. L'. DALE ARTIFICIAL mum) Filed Jan. so, 1946 INVENTOR.Fran/6L.fldle mamas E L A D [m F ARTIFICIAL HAND 2 Sheets-Sheet 2 FiledJan. 30. 1946 M m m m MN, Z

. Il lflllllflilll'lfllllllllllllll n I. u I a n w m Q 23!! 5 9 w l .7 Hm m m ww m Patented Dec. 1948 UNITED STATES PATENT OFFICE o,((1;:i:f:;alNo. 644,359 I Application January 3 1 Claim. 3

This invention relates to artiflcial limbs, and more particularly to anartificial hand which may be used with a natural or artificial arm.

At the present time artificial hands do not resemble a human hand ,andin most instances depend upon a three-pronged or hooked member toperform the function required.

An object of this invention is to provide a hand which to outwardappearances resembles a human hand and which will function as nearly aspossible in the same manner as a human hand. It is my purpose to providea hand with four fingers and a thumb which may be so manipulated so thatthe fist can be closed and held closed about an object without unduediscomfort to the wearer.

A further object is to provide a hand in which the relationship betweenthe thumb and the respective fingers is such that when the thumb and onefinger engage an object the other fingers will close naturally in thesame manner as the human hand. Most artificial hands that are availabletoday are operated and depend for their operation-upon the action ormovement of the opposing arm or shoulder and'require that the wearermaintains his upper body in a somewhat semi-rigid position in order tohold the hand in any predetermined position. It is one of the Purposesof this invention, therefore, to provide means for operating my improvedhand which will be totally independent of everything except the shoulderor upper arm of the wearer and the relationship of that member to thebody.

While I have disclosed a hand which'is attached to a human arm below theelbow, my hand can be attached to an artificial arm above the elbow aslong as the shoulder and armpit are left and, in fact, can be attachedto any artificial 'arm and operated by another portion of the body.

In the accompanying drawings- Fig. 1 is a view partly in cross-sectionshowing a preferred iorm of my hand.

Fig. 2 is a view in detail of the finger operating mechanism.

Fig. 3 is an enlarged detail in cross-section showing the operation ofthe fingers.

Fig. 4 is a cross-sectional view taken on the line 4-4 of Fig. 3.

Fig. 5 is a somewhat enlarged cross-sectional view of the bag designedto supply pressure to operate the hand.

Fig. 6 is a view showing a modified means for operating my hand.

Fig. '7 is a further modification. 7 Fig. 8 is a detailed view of partof the mechanism shown in Fig. 7 taken on the line wt of i2 or by anyother suitable means. The fitting ii Fig. 9.

' Fig. 9 is a view taken on the line 9-9 of Fig. 8. Referring moreparticularly to the drawings, my improved hand I0 is adapted to beattached to a'fitting II by means of a simple baynot plug will, ofcourse, have to be made to fit the stub i l of the arm B5. The entirehand and the fitting are coveredwith an outer covering extending fromthe fingertips to the upper part of the fitting which may be made ofrubber or other flexible material resembling skin. Through the fittingIi is a channel iii to accommodate the tube I9.

The tube i9 communicates with the bag 20 made of air-tight material andpositioned between the stra n 2i about the shoulder under the armpit ofthe wearer against the body 22. The bag 20 is provided with a spring 23which bears against a simple valve 24 having'a seat 25 to normally openthe valve to allow the bag to fill with air. The valve 24 is positionedagainst the inside of the arm of the wearer so that when pressure isapplied against the arm the valve 24 will close and air will be forceddown the tube l9.

The hand, itself, is made of a rigid casting of plastic or aluminum towhich the fingers 3i, 32, 33 and 34 and the thumb 35 are hinged. In thedetailed view shown in Fig. 3 the hinge 38 represents the knuckle joint.The hinge 31 corresponds to the middle joint and the hinge 39 to theouter joint of each finger. The fingers may be made of hollow tubularmaterial or of sheet metal pressed into channel shape. Extending througheach finger is a spring cable 40 which is fastened by means of pins H,or otherwise, to the tip of the finger. The spring member 40 extendsthrough a channel 42 which is located at the inner. side of the fingerso that when tension is placed upon the cable 40 the finger will becaused to bend in the same manner as the human finger. Each of thecables in the fingers is engaged by an arm, the cables in the fingers 3|and 32 being engaged by an arm 45, the cables in the fingers 33 and 84being engaged by an arm 45. The arms 45 and 46 are in turn engaged bythe pivotal links 41 and 48 to the arm 49, which, in turn, are connectedby the link 50 to the lever 5i. The lever ii is pivoted at one end tothe link 52 fastened to the casting 80.

Mounted within the casting 30 is a block 55 containing a cylinder 55 anda cylinder 51. Within the cylinder 56 is a shaft 58 upon which thepiston 59 slides. The piston 59 is provided with a gasket 60 to insurecontact. The shaft 58 is hollow and provided at its top end with anopening 62 into the cylinder 56, which terminates in a 1 nipple 63 towhich the tube- I9 may be clamped.

Mounted in the cylinder 51 is apiston 65having a gasket 66 and operatingagainst the spring 61. A vent 66 is provided for the passage of air. Arod 69 extends through the packing "from the piston 65 to engage thelever The thumb cable 'II is attached directly to the end 12 of thelever 6 I When the hand is extended the piston 59 will be at the upperend of the cylinder 56 while the piston 65 will be at thelower end ofthe cylinder 51. In Fig. 2 they are shown in the halfway position. Afiuid, such as'oil. is positioned below both pistons and passes throughthe openin as the pistons change their relative positions. If the wearerdesires to pick up an object such as a glass, he would reach for it inthe normal way and then exert pressure with his upper arm against thebag 20, thus forcing air from the bag through the tube I9 into thecylinder 56, causing the piston 59 to force the fiuid from the cylinder56 into the cylinder 51 through the opening I5 which, in turn, forcesthe piston 65 upwardly, exerting pressure on the lever 5| and throughthe yoke arrangement to the respective fingers and thumb cables causingthe hand to close about the glass. If an object of some weight is to bepicked up so that the grip must be secure, the wearer may pumpadditiona1air into the cylinder 56 by releasing the bag and allowing it to fill.The opening I5 is of such a nature that the oil will not flow back asquickly as the air bag can be refilled and pressure again exerted on it.It will be appreciated, therefore, that considerable pressure can beexerted and a firm grip established on any object desired. If an objectsuch as a pencil is to be picked up by the thumb and forefinger theaction of the yoke arrangement on the linkage between the arms 45, 46,49 and the leather is such that when the thumb and forefinger havecontacted the pencil the pressure is forced to the other fingers and theremaining three fingers will close naturally. By the same token, if thethumb and first two fingers engage an object, the opposition encounteredwill cause the yoke arrangement to transfer further movement to the lasttwo fingers so that they will close in a natural position. Where anobject which is irregular in shape is grasped by the entire hand thetubular yoke arrangement will cause the pressure to be transferredequally to all fingers to allow for the irregularity.

As heretofore stated, the entire mechanism from the knuckle to above thewrist is mounted in a casting and the fingers hinged to said casting.The entire device is then encased in a removable padded glove of rubberor skinlike material which extends above the fitting block I I.Artificlal nails can be mounted in the glove member and the glove membercan readily be removed for cleaning or replacing.

It will also be appreciated that while I have a shield member 60 havinga hinge 8| is attached to the armpit by means of the straps 62. Hingedto the shield at 63 is a similar hinged member 66. Each of the members64 and 86 are hinged together at 61 and attached to the cable 66. Thecable 88 runs directly to the lever 5| so that when the arm is movedinwardly the hinge 61 is moved upwardly toward the armpit to exertpressure on the cable 68 and, in turn, on the lever 5|, which will closethe hand in the manner heretofore described. In the form shown in Fig. 7the leather 5| is engaged by a. cable 90 mounted on the drum 9|. Thedrum BI is mounted on the shaft 92 which carries a bevelled gear 93meshing with the bevelled gear 94 on the shaft sicontrolled by theflexible cable 96. This cable 96 extends into the box 91 and engages theshaft 96 upon which is mounted the gear 99, and which is supported bythe bracket I00. The gear 99 engages the gears IN and I02 mountedrespectively on the shafts I03 and I04 which carry the pinions I05 andI06 engaged by the racks I01 and I06. The racks I61 and I08 are mountedon a contact member I09, normally spaced from the box 91 by means of thesprings IIO on the pins III and H2 and on the pin II4. When the contactmember I09 is pressed against the body the rack will cause the pinionsto turn on the shafts I03 and I04. This rotation will be transmittedthrough the gear 99 from the shaft 98 to the cable 96 and, in turn,through the gearing to the drum 9|, shortening the cable 90 and exertinga pulling motion on the leather 5|. The springs Hi can be added tosupplement the linkage and to give greater flexibility.

It is understood that while I have shown this means for actuating myhand the function of the hand is substantially the same and the relative-rnovement of the fingers depending upon their contact with an objectresults in each case from the double yoke arrangement whereby whencertain fingers meet opposition the other fingers being free to movewill close naturally and all four fingers and the thumb can be used tosimulate the natural hand much more closely than has heretofore beenpossible.

In addition to the equalizing members, or yoke arrangement, it ispossible with my hand to use a covering which will more nearly resemblethe human hand in appearance as well as in color and consistency.

I claim:

In an artificial hand having a thumb'and four fingers, members forclosing each finger, each of said members engaging one end of one of apair of arms, linkage between said pair of arms and athird arm andadditional linkage between said third arm and a lever, means foroperating said lever to transmit through said linkage and said armstension on said retractable members to close said hand, said meanscomprising a pair of cylinders mounted in said hand, pistons in saidcylinders, one of said pistons having a shaft engaging said lever andmeans for forcing air into the other of said cylinders to force fluidfrom said cylinder into the other cylinder to operate the Piston in saidcylinder comprising a bag worn between the arm and body of the wearer, avalve in said bag controlled by the wearer and a, tube communicatingfrom said bag to said cylinder whereby the'exertion of pressure againstsaid bag will force air out of said bag through said tube into saidcylinder to operate said pistons.

FRANK L. DALE.

(References on followIng page) REFERENCES CITED The following refrencesare of record the tile of this patent:

UNITED STATES PATENTS Number Name Date 42,515 Snellerberg Apr. 26, 186451,238

Snellerberg Nov. 28, 1865 Number 6 Number

